Hi,
if I wanted to cut a hole from 3" to 6" could a macro be written in Mach to do the trig to figure out the angular movements, and maintain a constant surface feed of the torch as it moved from the small diameter to the larger diameter?
wow I can see a lot of math !
There is indeed some mathmatics....but you don't have to do it.
In Gcode there is a movement called G02 which does a circular move of programmable radius about a programmable centre
at a programmable rate, so easy!.
In addition to cutting circles you could program it to cut a mixture of straight lines and circles to any required shape you want.
Have a look at the 'Road Runner' example that ships with Mach3. The two axis machine I've described could cut the Road Runner
shape just as easily as a circle.
Craig